Polio Outbreak Response Research Articles

Wastewater Surveillance for Poliovirus in Selected Jurisdictions, United States, 2022-2023.

Wastewater testing can inform public health action as a component of polio outbreak response. During 2022-2023, a total of 7 US jurisdictions (5 states and 2 cities) participated in prospective or retrospective testing of wastewater for poliovirus after a paralytic polio case was identified in New York state. Two distinct vaccine-derived poliovirus type 2 viruses were detected in wastewater from New York state and New York City during 2022, representing 2 separate importation events. Of those viruses, 1 resulted in persistent community transmission in multiple New York counties and 1 paralytic case. No poliovirus was detected in the other participating jurisdictions (Connecticut, New Jersey, Michigan, and Illinois and Chicago, IL). The value of routine wastewater surveillance for poliovirus apart from an outbreak is unclear. However, these results highlight the ongoing risk for poliovirus importations into the United States and the need to identify undervaccinated communities and increase vaccination coverage to prevent paralytic polio.

Novel Oral Polio Vaccine Type 2 Use for Polio Outbreak Response: A Global Effort for a Global Health Emergency.

A sharp rise in circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks in the years following the cessation of routine use of poliovirus type 2-containing oral polio vaccine and the trend of seeding new emergences with suboptimal vaccination response during the same time-period led to the accelerated development of the novel oral polio vaccine type 2 (nOPV2), a vaccine with enhanced genetic stability and lower likelihood of reversion to neuroparalytic variants compared to its Sabin counterpart. In November 2020, nOPV2 became the first vaccine to be granted an Emergency Use Listing (EUL) by the World Health Organization (WHO) Prequalification Team (PQT), allowing close to a billion doses to be used by countries within three years after its first rollout and leading to full licensure and WHO prequalification (PQ) in December 2023. The nOPV2 development process exemplifies how scientific advances and innovative tools can be applied to combat global health emergencies in an urgent and adaptive way, building on a collaborative effort among scientific, regulatory and implementation partners and policymakers across the globe.

Polio outbreak response, Yemen.

A decrease in vaccine coverage in conflict-affected areas has placed Yemen at higher risk of polio outbreaks caused by vaccine-derived poliovirus strains. In response to polio outbreaks, the Yemeni health ministry and partners initiated multiple vaccination campaigns to deliver vaccines to children. We also implemented several measures to enhance communication, education, health promotion and hygiene, especially in camps for internally displaced people. In 2009, Yemen achieved polio-free status and maintained it until 2019. However, the ongoing political conflict since 2015, coupled with challenges in delivering the polio vaccine to conflict-affected areas, resulted in two polio outbreaks: 35 cases caused by vaccine-derived poliovirus strain 1 between 2019 and 2021, and 230 cases due to vaccine-derived poliovirus strain 2 between November 2021 and December 2022. In response to the first outbreak, by the end of 2020, we vaccinated 7.2 million children through nationwide vaccination campaigns, except in Sa'ada governorate due to a ban by the authorities. By the end of 2021, 3 800 313 children younger than 5years had received polio vaccines. For the second outbreak, by the end of 2022, 4 463 389 vaccines had been given to children younger than 10years, and 1 217 423 to those younger than 5years. Vaccination campaigns in conflict-affected areas with low vaccine coverage remain crucial in eradicating polio. Efforts are needed to reach vulnerable groups such as displaced populations. Advocacy, communication and social mobilization actions help ensure broader public inclusion and participation in vaccination efforts to prevent polio outbreaks.

Analysis of a Sabin-Strain Inactivated Poliovirus Vaccine Response to a Circulating Type 2 Vaccine-Derived Poliovirus Event in Sichuan Province, China 2019-2021

The Sabin-strain inactivated poliovirus vaccine (IPV) may be a tool for polio outbreak response in certain situations. To investigate the response to a type 2 vaccine-derived poliovirus (VDPV2) outbreak. This case series was conducted in China after a VDPV2 was detected in stool specimens from a child with acute flaccid paralysis (AFP) in Sichuan Province in 2019, 3 years after the global withdrawal of live, attenuated type 2 oral poliovirus vaccine (OPV). Investigation followed National Health Commission and World Health Organization guidance and included searching hospitals for unreported AFP cases; testing stool specimens from the child, his contacts, and local children; enhanced environmental surveillance for VDPV2s in wastewater; and measuring vaccination coverage. Sabin-strain IPV campaigns were conducted in a wide geographic area. Any VDPV2 detection after completion of the supplementary immunization activities. A 28-nucleotide-change VDPV2 was isolated from a young boy. Three VDPV2s were detected in healthy children; 2 were contacts of the original child, and none had paralysis. A search of 31 million hospital records found 10 unreported AFP cases; none were polio. No type 2 polioviruses were found in wastewater. Prior to the event, polio vaccine coverage was 65% among children younger than 5 years. Sabin-strain IPV campaigns reached more than 97% of targeted children, administering 1.4 million doses. No transmission source was identified. More than 1 year of enhanced poliovirus environmental and AFP surveillance detected no additional VDPVs. These findings suggest that the circulating VPDV2 outbreak in 2019 was associated with low vaccine coverage. An investigation discovered 3 infected but otherwise healthy children and no evidence of the virus in wastewater. Following Sabin-strain IPV-only campaigns expanding from county to prefecture, the poliovirus was not detected, and the outbreak response was considered by an expert panel and the World Health Organization to have been successful. This success suggests that the Sabin-strain IPV may be a useful tool for responding to circulating VDPV2 outbreaks when high-quality supplementary immunization activities can be conducted and carefully monitored in settings with good sanitation.

Lessons Learnt from Interregional and Interagency Collaboration in Polio Outbreak Response in the Horn of Africa.

Following the outbreak of poliovirus in the countries in the Horn of Africa, Somalia, Kenya and Ethiopia, in two WHO regions, an outbreak response involving the WHO Africa and WHO East and Mediterranean Regions and partner agencies like the UNICEF in East and Southern African was developed. This paper documents response to polio virus outbreak in the Horn of Africa and the lessons learnt for the interregional and inter-agency collaboration on the response. This collaboration led to speedy interruption of the outbreak and within a period of one year the total virus load of 217 in 2013 was brought down to mere six. This resulted from collaborative planning and implementation of activities to boost the hitherto low immunity in the countries andimprove surveillance among others. A number of lesson were generated from the process. Some of the lessons is critical role such collaboration plays in ensuring simultaneous immunity boosting, information and resources sharing, among other. Some challenges were equally encountered, chiefly in the appropriation of authorities. In conclusion, however, one is safe to note that the collaboration was very fruitful given the timely interruption of transmission.

Overview of Polio Outbreak Response in Kenya, 2013 to 2015.

BackgroundGlobally, tremendous improvement has been made in Polio eradication since its inception in 1988. For the third time in a decade, Kenya has experienced a Polio outbreak along the border with Somalia. The affected areas were in Garissa County, replete with previous occurrences in 2006 and 2012. This article, give an account of series of events and activities that were used to stop the transmission within 13 weeks, an interval between the first and the last case of the 2013 outbreak.MethodsIn an attempt to stop further transmission and time bound closure of the outbreak, many activities were brought to fore: the known traditional methods, innovative approaches, improved finances and surge capacity. These assisted in case detection, implementation, and coordination of activities. The external outbreak assessments and the six-monthly technical advisory group recommendations were also employed.ResultThere were increased case detections of >=2/100,000, stool adequacy >=80%, due to enhanced surveillance, timely feedbacks from laboratory investigation and diagnosis. Sustained coverage in supplemental immunisation of > 90%, ensured that immune profile of >=3 polio vaccine doses was quickly attained to protect the targeted population, prevent further polio infection and eventual reduction of cases coming up with paralysis.ConclusionOverall, the outbreak was stopped within the 120 days of the first case using 14 rounds of supplemental immunisation activities.

Effectiveness of the Horn of Africa Polio Outbreak Coordination Office in Nairobi, Kenya.

BackgroundThe WPV1, first detected in Somalia in April 2013, quickly spread to Kenya and Ethiopia and triggered a multi-country coordinated effort. In February 2014, a formal HoA Polio Outbreak Coordination Office was established by WHO AFRO and WHO EMRO in Nairobi to provide technical and managerial leadership. An independent assessment was conducted to ascertain the usefulness of the HoA Coordination in response to the outbreaks.MethodsThe independent assessment team conducted desk review of the rules and guidelines forming the HoA Coordination office and committee. It also reviewed minutes of meetings and interviewed various stakeholders at the Regional levels.ResultsThis independent review of the work of the office, in September 2016, showed that the office was fully functional and had benefited from financial and technical support from regional and global GPEI partners. The office is based in the WHO Kenya Country Office which also provides administrative, logistics and until August 2016, data management support. The close working relationship with technical partners ensured alignment and close coordination of outbreak response activities. The mechanism also allowed partners to identify areas of work based on their expertise and avoided duplication of efforts at the local level. Overall, the office was effective in close monitoring of implementation of the outbreak response, strengthening of cross-border activities, monitoring implementation of the TAG recommendations, improving SIA planning and quality, and expanding independent monitoring in Somalia and South Sudan. Key constraints included limited office space for day-to-day operations, and disruption of some activities due to interruption of contracts of technical staff. However, the closure of the HoA outbreak in August 2015 led to some complacency, resulting in a lost sense of urgency, negatively impacting the coordination.ConclusionsThe HoA Coordination Office should continue to function into the foreseeable future. To ensure sustainability of activities, the technical staff should be given contracts for a minimum of 12 months. The Office should reintroduce and schedule the Joint Polio Outbreak Response team meetings at least once every three months.

Establishment and Use of Polio Communication Network in Response to Polio in Outbreak Countries of the Horn of Africa: 2013-2014.

BackgroundBetween 2013 and 2014, the Horn of Africa countries experienced a severe and prolonged outbreak of polio viruses. It started in one district in Somalia but quickly became a national and even international disaster, crossing international boundaries into Kenya and Ethiopia. This paper documents experiences in the establishment and contributions of the Polio Communication Network (PCN) to the polio outbreak response in the outbreak countries of Somalia, Kenya and Ethiopia from 2013 to 2015.ProcessThe establishment of the PCN network of partnerships and technical assistance was designed to implement a strategic communication response. Various strategies were used to establish the PCN. Some of these strategies included partnerships with faith-based organizations; involvement of local leaders in microplanning; social mobilization committees and research, monitoring, evaluation and documentation structures.Major OutcomesPCN contributions through sustained high levels of community awareness of polio rounds were demonstrated. The contributions of the context-sensitive approaches included significant gains in reaching traditionally missed, hard-to-reach, pastoral communities with polio information, improved communication capacity, and successful closure of the outbreak within the expected timeline. This PCN experience provides important communication lessons relevant to polio eradication and other public health programmes. The focus on building capacity in areas such as monitoring, and data collection generated social data that led to the communication approaches making a significant impact. PCN contributed to a better understanding of the behavioral and environmental factors affecting the demand for, and uptake of, health services in the HoA which can be extended to most of the countries in the HoA with the same demographic and epidemiological realities.ConclusionThe use of the PCN helped bring the 2013-2014 polio outbreak under control and illustrates how the PCN can help drive progress towards the realization of the agenda of the universal health coverage and vision 2030 agenda in the African Region and elsewhere.

Supporting polio outbreak response through mathematical modelling

Supporting polio outbreak response through mathematical modelling

Polio Outbreak Response; Evaluation of Acute Flaccid Paralysis Surveillance in Karbala, Iraq.

Background:After the last outbreak of wild polio infection in Baghdad, April 2014, the Iraqi response to the outbreak was activated through solid surveillance of Acute Flaccid Paralysis (AFP) case detection in all governorates to interrupt the circulation of poliovirus in addition to the strengthening of Expanded Program on Immunization. This response to the last outbreak has to be evaluated independently to ensure effective mopping and surveillance to stop further outbreak all over the country including the holy province Karbala. We aimed to evaluate the response to the last polio outbreak by evaluating surveillance activities of acute flaccid paralysis cases whether they meet the recommended standards.Methods:Observational evaluation study conducted through August 15–25, 2015. Checking of Acute Flaccid Paralysis surveillance (AFP) activity through detection of nonPolio acute flaccid paralysis rate and immediate reporting with adequate stool sampling, and 60 days follow-up examination four districts of the province. The reviewing checked whether the surveillance system in Karbala met the global standards required for stopping wild poliovirus circulation. The evaluation included immunization coverage rates and active National Immunization days of oral polio vaccine campaigns.Results:During the period of review, the core surveillance indicators in Karbala met the globally set standards. Percent of acute flaccid paralysis cases with specimens reached to the reference laboratory within 3 days was 100%. Nonpolio cases was 4.2 per 100000 population under 15 years of age through week 33 of the year 2015. Eleven AFP cases were reported from all districts of Karbala among Population of children under 15 years of age. The percentage of cases with adequate specimens was 100% in 2015 versus 93% in 2014. The percent of AFP Cases notified within 7 days of paralysis onset (during first 33 weeks) was 100% in 2015 versus 87% in 2014.Conclusions:As Karbala response to polio outbreak met the target global indicators and standards of polio surveillance. The circulation of the virus in this locality was interrupted and further transmission of the disease is unlikely.

Estimating population immunity to poliovirus in Jordan’s high-risk areas

ABSTRACT A community-based serosurvey was conducted among children ages 6–59 to assess population immunity in Jordan’s high-risk areas following the Middle East polio outbreak response. The survey was a two-stage cluster-quota sample with high risk areas as the primary sampling units. High-risk areas included border and hard-to-reach areas, and areas with a high proportion of refugees, mobile communities and/or low coverage during previous immunization campaigns. Population immunity to poliovirus was high overall. In high-risk areas, Type 1 seroprevalence = 98% (95% CI = 96, 99), Type 2 = 98% (95% CI = 96, 99) and Type 3 = 96% (95% CI = 94, 98). Seroprevalence was higher in the refugee camps: Type 1 seroprevalence = 99.6% (95% CI = 97.9, 100); Type 2: 99.6% (95% CI = 97.9, 99.9), and Type 3: 100% (95% CI = 100,100). The vigilance that the Jordan Ministry of Health has placed on locating and vaccinating high-risk populations has been successful in maintaining high population immunity and averting polio outbreaks despite the influx of refugees from Syria.

Designing and implementing an electronic dashboard for disease outbreaks response - Case study of the 2013-2014 Somalia Polio outbreak response dashboard.

In April 2013, a case of wild polio virus (WPV) was detected in the Somalia capital Mogadishu. This inaugurated what is now referred to as the 2013-2014 Horn of Africa Polio outbreak with cases reported in Somalia, Kenya and Ethiopia. By the notification of the last polio case in August 2014, 223 cases of WPV had been reported in Somalia, Kenya and Ethiopia of which 199 in Somalia alone. The outbreak response required timely exchange of information between the outbreak response coordination unit (in Nairobi) and local staff located in multiple locations inside the country. The need to track and timely respond to information requests, to satisfy the information/data needs of polio partners and to track key outbreak response performance indicators dictated the need to urgently set up an online dashboard. The Somalia Polio Room dashboard provided a graphical display of the polio outbreak data to track progress and inform decision making. The system was designed using free and open sources components and seamlessly integrated existing polio surveillance data for real time monitoring of key outbreak response performance indicators. In this article, we describe the design and operation of an electronic dashboard for disease surveillance in an outbreak situation and used the lessons learned to propose key design considerations and functional requirements for online electronic dashboards for disease outbreak response.

The Polio Communication Network Contribution to the Polio Outbreak Response in Ethiopia’s Somali Region, 2013–2015

This article explores the Polio Communication Network’s (PCN) contribution to the polio outbreak response in the Somali Region of Ethiopia from 2013 to 2015. The PCN strategies and innovations include the establishment of a communication network of experts, development of partnerships with locally trusted and influential groups, and capacity building of local structures. Results show PCN contribution through sustained high levels of community awareness of polio rounds and low rates of noncompliance with polio vaccination in line with the national indicator (< 1%). We argue that the context-sensitive approaches made significant gains in reaching traditionally missed, hard-to-reach, pastoral communities with polio information, improved communication capacity, and expertise, and contributed to the successful outbreak closure. The PCN experience in the Somali Region, one of Ethiopia’s lowest-performing regions for health indicators, provides important communication lessons for the long term relevant to polio ...

Polio Outbreak Response in Ethiopia

Ethiopia had been polio-free for almost four years until December 2004. However, between December 2004 and February 2006, 24 children were paralysed as a result of infection with wild poliovirus imported from the neighbouring country of Sudan. In response, the country has attempted to document the impact of various response measures on the containment of wild poliovirus transmission. This study aims at systematic and epidemiological assessment of the extent of the outbreak, its determinants, and the lessons learned as well as the implications for future control strategies to interrupt wild poliovirus transmission. A cross-sectional study design with qualitative and quantitative data collection approaches was used to conduct the epidemiologic assessment. All confirmed wild poliovirus cases, and reported acute flaccid paralysis cases in close proximity to the confirmed polio cases were the study subjects. Child caretakers and health service providers were interviewed as part of the investigation. Between December 2004 and February 2006, eight children from Tigray Regional State, nine children from Amhara Regional State and seven children from Oromia Regional State were paralysed as a result of infection with wild poliovirus type 1. Genetic sequencing demonstrated two separate importations to Ethiopia. Risk factors that may have facilitated spread of the outbreak within the country included gaps in vaccination coverage and interruption of the cold chain system, gaps in acute flaccid paralysis surveillance performance, high population mobility, poor environmental sanitation, crowded living conditions and unsafe drinking water. In response to the outbreak, Ethiopia conducted detailed outbreak investigations within two days of confirmation of the index cases. Large-scale, house-to-house vaccination campaigns were also implemented. As a result, the three regions interrupted the wild poliovirus transmission within the regions within one year of confirmation of the index case. Outbreak response activities were successful in interrupting the imported wild poliovirus transmission in Tigray, Amhara and Oromia Regional States of Ethiopia within a one-year period of time. In Ethiopia, programme strategies should be intensified to contain further spread and prevent future importation of wild poliovirus. Large-scale immunisation campaigns should reach every child, including those isolated by geography, poverty and security.

Interrupting poliovirus transmission – New solutions to an old problem

Since the launch of the Global Polio Eradication Initiative (GPEI) in 1988, knowledge as to the nature of circulating polioviruses and the challenges to their interruption has increased tremendously, particularly during the period 2000–2005. By January 2006, however, the systematic application of the standard polio eradication strategies, combined with recent refinements, had reduced the number of countries with ongoing transmission of indigenous wild polioviruses to just four (Nigeria, India, Pakistan, and Afghanistan), the lowest ever in history. In addition, only 8 of the 22 areas that had been re-infected by wild poliovirus in 2003–2005 still required large-scale ‘mop-up’ activities and circulating vaccine-derived poliovirus (cVDPV) outbreaks were being readily addressed. This progress, despite new challenges late in the GPEI, was greatly facilitated by a range of solutions that included two new monovalent oral polio vaccines (mOPVs), new and robust international standards for polio outbreak response, and renewed political commitment across the remaining infected countries.